I am not surprised at all that someone has finally attacked them. This is not just an ordinary organization destroying documents, leaking their own sources or suing others for doing what they themselves want us to believe is our duty, ie. leaking confidential documents. This is much more. This is ignoring the fact that people are literally risking their lives because they believed WikiLeaks. I am surprised that it was only a DDoS attack and not a more serious form of revenge. This is what you get for totally disrespecting the lives and risks of the people thanks to whom you are now rich and famous. This is just Karma coming back to you. Not surprising at all.
The key elements in human thinking are not numbers but labels of fuzzy sets. -- L. Zadeh